Anti-Buzz: Sack of Topics 2011

I am playing the role of Santa this week. I have brought you a sack of toys. Well, a sack of topics anyway. There are things in the spirit of this column that don’t really lend themselves to a full article, but I’m itching to address them. So prepare yourself for a series of mini-buzzes.

The buzz: Macs are not PCs.

The anti-buzz: PC stands for “Personal Computer”

So unless Mac fans want to admit they aren’t using a real computer, this distinction is erroneous. It would be like Budweiser launching a “Bud Light vs. Beer” ad campaign; we’d all chuckle and ask, “so you admit that Bud Light isn’t beer?”

I’ll grant that referring to non-Macs as PCs is a pet peeve of mine and I’ll grant that I’m being a little pedantic by making light of it, and I’ll also grant that Apple isn’t entirely responsible for the labeling anyway, even if it was their ads that popularized the nomenclature. But there really is more at stake here. A few years ago the “Mac vs. PC” dichotomy was relatively harmless. Now consumers are offered many alternatives to personal computers, notably tablets and smart phones, and further gray areas forged by e-readers and music players.

Smart consumers need to be aware of what a personal computer is, and what it offers that tablets and smart phones don’t, (and vice versa). Smart consumers need to stop thinking that the opposite of a PC is a Mac, because it isn’t.

The buzz: Half of everything is above average.

The anti-buzz: No, half of everything is above median.

More from the math/science/statistics rant scene, the misuse of the word “average.” Perhaps it is not really misuse, but unfortunate ambiguity.

“Average” is actually a broad term, but it is colloquially used to indicate the arithmetic mean. It is not actually wrong to say “average” when you mean “median”, but it is not what most people understand when you use the word that way. A lot of people conflate properties of mean and median and lump them under the superconcept of “average” and then start to infer or say misleading things.

A thought experiment: Assume there are only 10 dentists in the world, and that you can score these dentists from 0 to 100. Assume that 2 of them score at 100, 3 of them score at 96, 3 of them score at 80, and 2 of them score at an embarrassing 11. In this world, the average dentist scores at 75, and 8 of 10 (or four out of five dentists 🙂 if you like) dentists are above average. What gets lost here is that the dentists who score 80 are among the worst half of dentists. Most people understand all this when you tell it to them so simply, but their day-to-day intuition always seems to revert back to thinking that “average” and “median” are the same thing.

The buzz: Unix is an old-fashioned, text-only operating system.

The anti-buzz: Today, Unix is a standard, and many things follow it.

This could be an article by itself, but it would easily be the most boring thing I have ever written. It can be a tendency to think of old text-and-arrow-keys applications when you hear the word “Unix.” When a modern operating system claims to be Unix, it can seem laughable to think that some enthusiasts are hunched over a blinking rectangular cursor and calling themselves “power users.” And if that were actually the case then Unix definitely would be laughable.

However, Unix is really just an operating system standard. Mac OS X is a Unix system. Linux is a Unix system. Google’s Chrome OS is a Unix system. For the typical user, all of the similarities are under the hood. Explaining it all is beyond the scope of this column.

If you want a quick takeaway on what the Unix standard means, the inside joke is that in Unix, everything is a file. The pipe between two processes is a file. The stream of data from your hardware is a file. All of your keyboard input is a file. Folders are files. Everything is a file. Now you know!

The buzz: Science is either good (right) or bad (wrong).

The anti-buzz: Actually, a lot of science is just mediocre.

I took up arms over common misinformation in popular science and statistics, but there is a broader, more abstract misconception that plagues the popular notion of science. Psychological studies on why male college students like pancakes more than female college students are easy enough to dismiss as harmless, regardless of their veracity. A lot of pop science is fluff.

However, sometimes it is not fluff. Sometimes it becomes politicians arguing over the results of studies on greenhouse gases. Sometimes it affects public policy, and when science becomes political, things get polarized.

So it is easy to forget that scientific results and scientific dialog are rarely so black and white. Most science is mediocre; one wonders why a particular strategy was used, or if a set of results isn’t a little underwhelming, but rarely does it happen that research is deemed “correct” or “incorrect”. Insight into universal truth rarely comes, and dismissal of “flawed” research would stymie a lot of progress.

The buzz: Virtual Memory allows you to have as much RAM as you need.

The anti-buzz: And you can just keep hitching trailers to the back of your car and have as much trunk space as you need too.

Many people are excited to learn that memory is interchangeable. It is. To a computer, all memory is just memory. You need temporary memory to juggle the tasks at hand, and you need permanent memory to store your files and data and applications for later use. And to this end you can use part of your hard disk as “virtual” memory – memory that bolsters your temporary memory, commonly referred to as “RAM”, (although “random-access memory” actually applies to everything that is rewritable and arbitrarily navigable, from magnetic tapes to solid state drives).

So, it’s true, your machine can effectively have more RAM by setting aside part of your hard disk. The revelation is that you don’t really want to. Such “virtual” memory, (scare quotes because there is nothing virtual about it – it’s memory), is for emergencies only. Hard disk access is sloooooow. If we slowed down time, and let one processor cycle take one second, then the amount of time it takes to retrieve data from traditional RAM is about 15 seconds, and the amount of time needed to retrieve data from a hard disk is 300 years. The difference is indeed that stark.

So the next time you take solace in your virtual memory, remember that the opposite is actually what happens more often: Parts of your hard disk are cached into your speedier temporary memory and manipulated there, written back to the real hard disk only when it is convenient. This gives a huge performance gain, and it is also why doing things like shutting off your computer without selecting “shut down” from some menu, or yanking out a flash memory stick without properly “ejecting” it can result in the loss of data. What you really need isn’t virtual memory, it’s virtual hard disk.